Blood clots often form silently—but when they block critical blood vessels, they can trigger a heart attack or stroke without warning. Understanding the early signs and knowing how to lower your risk could help save your life.

Thrombosis Risk Groups

It’s a common misconception that blood clots affect only older people. In reality, certain younger people may also face a high risk. The following factors significantly increase the likelihood of developing blood clots:

• Inactivity: Sitting for long periods can lead to poor circulation and “sticky” blood, increasing the risk of clots. Get up and move for at least five minutes every hour to support healthy blood flow.


• Obesity: Excess body weight increases pressure on veins and slows blood return to the heart, raising the risk of deep vein thrombosis by about 2.5 times.


• Cardiovascular risk factors: High blood pressure, high cholesterol, and high blood sugar can damage blood vessels and platelets, contributing to clot formation.


• Smoking: Chemicals in cigarettes harm the inner lining of blood vessels and promote clumping of blood cells, making clot development more likely.

Early Warning Signs of a Blood Clot

Blood clots often develop with warning signs. Pay attention to the following symptoms:

Temporary Blurred Vision

People over age 65 are especially prone to temporary blurred vision. While they may normally see clearly, sudden blurred vision may signal thickened blood that’s not delivering enough oxygen and nutrients to the retina and optic nerve.

Purple Lips and Tongue

Having purple lips and tongue may suggest poor blood circulation and sticky blood, a condition known as “blood stasis” in traditional Chinese medicine.

Shortness of Breath While Squatting

When blood flow is affected by blood clots, it may cause symptoms such as breathlessness and chest tightness. People with obesity should take note if their breathing becomes difficult during or after squatting.

If you experience any of these symptoms, seek immediate medical attention to help prevent serious cardiovascular complications. Paying attention to these early warning signs is crucial, as a blocked blood vessel may lead to a stroke in the brain, a myocardial infarction in the heart, a pulmonary embolism in the lungs, or a hepatic hemangioma in the liver.

3 Foods That Support Blood Vessel Health

After age 50, it’s especially important to support vascular health and reduce blood viscosity through dietary choices. The following three foods may help:

1. Onions

Onions may lower blood viscosity. They are rich in flavonoids and sulfur-bearing compounds like quercetin, which have antioxidant, anti-inflammatory, lipid-lowering, and anti-clotting properties.

For better absorption, stir-fry onions in oil—fat-soluble compounds like quercetin are more easily absorbed when cooked with fat.

2. Tomatoes

Tomatoes help prevent blood clots and lower cholesterol. The yellow gel around tomato seeds inhibits clumping of blood cells, reducing clot risk. Raw tomatoes offer the best anti-clotting effects, while cooked tomatoes release more lycopene, which supports heart health.

3. Black fungus

Black fungus supports blood vessel health. It is rich in polysaccharides, which have antioxidant and lipid-lowering effects.

Try boiling black fungus with red dates to make a sweet soup that promotes circulation and strengthens cardiovascular function.

Critical Times to Protect Your Heart

The incidence of heart disease typically spikes in winter, with sudden deaths peaking late at night and early mornings. Being mindful of specific times and routines can help reduce the risk of sudden cardiac events.

1. Upon waking 

Cold environments cause blood vessels to constrict, increasing cardiovascular risk. Before getting out of bed, put on warm clothing and rise slowly to allow your body to adjust to the temperature.

2. While brushing your teeth or washing your face

Exposure to cold water in the morning may trigger blood vessel constriction by causing a sudden drop in temperature. Use warm water to help reduce strain on your cardiovascular system.

3. After bathing

The body remains warm and moist after a bath, making sudden cold exposure more dangerous. Dry off quickly and dress warmly to help retain body heat and avoid abrupt temperature changes.

Warning Signs of a Heart Attack and What to Do

A heart attack often strikes without warning, but the body may give early signals. Watch for the following signs and seek medical attention right away:

• Severe chest tightness or pain: If it lasts for more than five minutes, it may mean that blood vessels are seriously blocked, and you should seek emergency care right away.


• Unexplained stomach pain: Some people experience stomach discomfort a few days or even weeks before a heart attack.


• Back or shoulder pain: A heart attack can cause pain in the back or shoulder that has no obvious cause.


• Numbness or weakness in the arms: Poor blood flow may lead to numbness or a feeling of weakness in one or both arms.


• Prolonged chest tightness: If tightness lasts 15 to 20 minutes and does not go away, call 911  immediately.

Blood clots are often preventable. Understanding the risks, staying alert to early signs, and taking proactive steps—like staying active and eating circulation-boosting foods—can go a long way in safeguarding your heart and brain. Your awareness could be the difference between life and death, for you or a loved one.